The Rice University study was based on a side-by-side comparison of 10 human genetic models that each aim to determine when Eve lived using [...]]]> The most robust statistical examination to date of our species’ genetic links to “mitochondrial Eve” – the maternal ancestor of all living humans – confirms that she lived about 200,000 years ago.

The Rice University study was based on a side-by-side comparison of 10 human genetic models that each aim to determine when Eve lived using a very different set of assumptions about the way humans migrated, expanded and spread across Earth.

The research is available online in the journal Theoretical Population Biology.

The quest to date mitochondrial Eve (mtEve) is an example of the way scientists probe the genetic past to learn more about mutation, selection and other genetic processes that play key roles in disease.

For example, the way scientists attempt to date mtEve relies on modern genetic techniques. Genetic profiles of random blood donors are compared, and based upon the likenesses and differences between particular genes, scientists can assign a number that describes the degree to which any two donors are related to one another.

Using mitochondrial genomes to gauge relatedness is a way for geneticists to simplify the task of finding common ancestors that lived long ago. That is because the entire human genome contains more than 20,000 genes, and comparing the differences among so many genes for distant relatives is problematic, even with today’s largest and fastest supercomputers.

But mitochondria – the tiny organelles that serve as energy factories inside all human cells – have their own genome. Besides containing 37 genes that rarely change, they contain a “hypervariable” region, which changes fast enough to provide a molecular clock calibrated to times comparable to the age of modern humanity.

Because each person’s mitochondrial genome is inherited from his or her mother, all mitochondrial lineages are maternal.

To infer mtEve’s age, scientists must convert the measures of relatedness between random blood donors into a measure of time.

“You have to translate the differences between gene sequences into how they evolved in time,” said co-author Krzysztof Cyran, vice head of the Institute of Informatics at Silesian University of Technology in Gliwice, Poland.

Within each model, the answers to these questions take the form of coefficients – numeric constants that are plugged into the equation that returns the answer for when mtEve lived.

Each model has its own assumptions, and each assumption has mathematical implications. To further complicate matters, some of the assumptions are not valid for human populations. For example, some models assume that population size never changes.

That is not true for humans, whose population has grown exponentially for at least several thousand generations. Other models assume perfect mixing of genes, meaning that any two humans anywhere in the world have an equal chance of producing offspring.

Cyran said human genetic models have become more complex over the past couple of decades as theorists have tried to correct for invalid assumptions. But some of the corrections – like adding branching processes that attempt to capture the dynamics of population growth in early human migrations – are extremely complex.

Which raises the question of whether less complex models might do equally well in capturing what’s occurring.

Via: terradaily.com

The research, first in the world on the subject, was carried out by experts from Nascentis, a reproductive medicine center located in Córdoba, Argentina. The results [...]]]> Buenos Aires – Argentine researchers have found that radiation emitted by an Internet-connected computer resting on the user’s legs may affect male fertility by reducing sperm motility and fragmenting DNA.

The research, first in the world on the subject, was carried out by experts from Nascentis, a reproductive medicine center located in Córdoba, Argentina. The results of the study will be presented at the 66 Congress of the American Society for Reproductive Medicine (ASRM) taking place in October in Denver, USA.

The researchers led by Conrado Avendaño, a biochemist specializing in andrology, in collaboration with Ariela Mata, reproductive biology specialist and César Sánchez Sarmiento, director of the medical center, among others, demonstrated that the motility of spermatozoa is impaired when these cells are exposed to the radiation from laptops, according to a report published in the Córdoba newspaper “La Voz” (in Spanish).

For this study, the researchers evaluated semen samples from healthy donors with no history of recent illnesses. Each sample was divided into two equal fractions, which were placed in separate temperature-controlled rooms. One of the sub-samples was incubated under a laptop connected to the Internet, to replicate the conditions that occur when a man places the computer on his lap.

The findings are important because previous studies on reproductive medicine have shown that some of the problems in fertilization and embryonic development are caused by damage in the DNA molecules of the sperm.

While agreeing that further research on the matter is required, the researchers advise men to avoid holding laptop computers on the legs, “especially if they are connected to Internet through Wi-Fi.”

This research brings new knowledge on the effects of electromagnetic fields (EMF) on human health. EMF levels from Wi-Fi devices are much lower than those emitted by mobile phones, and there is less public concern on potential health issues for wireless LAN devices. The Health Protection Agency (HPA) claims that if a person spends one year in a Wi-Fi hot-spot, they will receive a dose of radio waves equivalent to a 20-minute call on a mobile phone.

Often wireless access points are in close proximity to humans, but the drop off in the already low power over distance is fast, following the inverse-square law (*). Nonetheless, the results of this study suggest that when a laptop is operated for long periods, the close proximity to the source of the EMF may affect a male user sensitive reproductive cells causing damage to DNA and reducing sperm cell motility.

Via: digitaljournal.com

Environmental rules require the company to put in place measures to prevent erosion before it starts digging, because the site is close to the shore.

“We now have a [...]]]> A plan by Ripley’s Believe It or Not to dig up a 13-metre sperm whale’s remains on the North Shore of P.E.I. has hit a few more snags.

Environmental rules require the company to put in place measures to prevent erosion before it starts digging, because the site is close to the shore.

“We now have a soil erosion problem that we weren’t prepared for. We are going to have to build some sort of retainment wall before we can dig,” said Edward Meyer, vice-president of exhibits and archives at Ripley Entertainment.

“We’ve had the government inspection. We know what we’re supposed to do. We’re waiting for some signatures and some rubber stamps and until that happens we can’t put a shovel in the ground.”

The delay means the dig might not happen this year.

The company buried the whale 21 years ago with plans to eventually recover it and display it. It’s buried on a property in the Darnley area, north of Summerside.

Ripley’s officials were on the Island last month to get things underway. There was some difficulty in locating the burial site, and concerns from the landowner to deal with.

Meyer said the landowner wants the digging done before the end of September, so unless the federal permit comes through in the next few weeks the dig will have to wait until next summer.

The whale skeleton will likely be housed in the Ripley’s Museum in Niagara Falls, Ont., said Meyer.
Via: cbc.ca

Blessed with a supremely talented and natural cast, director Lisa Cholodenko (“High Art”), writing along with Stuart Blumberg (“The Girl Next Door”), has fashioned a [...]]]> Definitions of family, love and friendship all get put to the test with wit and warmth in “The Kids Are All Right,” one of the year’s most honest and endearing films.

Blessed with a supremely talented and natural cast, director Lisa Cholodenko (“High Art”), writing along with Stuart Blumberg (“The Girl Next Door”), has fashioned a portrait of the modern family that manages to touch many buttons without hammering too hard on any one. You get a sense of the breadth of these people.

First there are the moms — longtime lesbian partners Nic (Annette Bening) and Jules (Julianne Moore). Nic is the responsible one, a physician who can turn to a few extra glasses of wine for strength. Jules is a dreamer, just now starting her latest career as a landscape designer. It helps the camera mightily that both women are beautiful.

And then there are their kids, the products of artificial insemination, both from the same anonymous donor.

Joni (Mia Wasikowska, far more impressive here than as Alice in “Alice in Wonderland”) has just graduated from high school and leaves for college at the summer’s end. Brooding jock Laser (Josh Hutcherson) seems a bit lost as the only male in the family, and he seems to want something more.

That something more, it turns out, is a father. Now that Joni’s 18, she can legally try to contact the sperm donor who contributed half their genetic makeup.

Prodded by Laser, she does just that, and the kids eventually meet up with Paul (Mark Ruffalo), a freewheeling, motorcycle-riding, organic health food restaurant-owning guy who had no idea somebody actually used his essential juices for procreation.

Then comes the inevitably awkward lunch where the kids bring their newly discovered dad home to meet the moms. Nic’s feathers are ruffled and she’s wary of this sudden interloper, while Jules seems more open to extending the family. When Paul hires Jules to landscape his backyard, you know complications are looming.

While the moms’ lesbian relationship isn’t pushed full forward — this is a family, first and foremost — it is used to wonderfully funny and humanizing effect. Not even the moms can explain their love of hardcore gay male porn, and they do have a certain cluelessness when it comes to dealing with Laser, which they at least sense.

Cholodenko combines the many modern elements in play here — the sexuality; the breezy California life style; Paul’s organic holiness and Peter Pan tendencies — with a deft mix of insight and cheekiness. And yet when it comes to dramatic moments — when the fragile family extension falters — “Kids” is as taut, touching and real as you could want.

It helps that Bening and Moore work so easily off one another — they are your basic long-loving, long-bickering married couple, each balancing the other. Moore, in particular, lets loose in this role, throwing body and soul into a character who’s both lost and found.

It’s probably a bit early to muse on Oscar nominations, but “The Kids Are All Right” is certainly a worthy contender, especially in the Best Actress race. The film slips a bit toward the end — of course, so do its characters — but its faith in the power of family and love endures. In the truest sense, this is the best family film of the year.

Via: detnews.com

University of Adelaide Professor Sarah Robertson, who is leading the research, says tests discovered that females have an [...]]]> The age old male view that women are too picky has been taken to a whole new level after research found the female reproductive system may be rejecting sperm it doesn’t find good enough to create a pregnancy.

University of Adelaide Professor Sarah Robertson, who is leading the research, says tests discovered that females have an in-built quality control system, that assesses if the male partner is quality enough to invest her reproductive energy in.

“Part of this whole process is it’s a way of the female body evaluating whether the time is right and whether this particular partner is the right one to conceive a pregnancy with.

“Some women have higher thresholds to responding to this signalling pathway. It might be that with one partner they’re having more trouble than they might with another partner.

“What we understand is that there is a partner-specific component to this. Some combinations of men and women might not be compatible and it’s possible that the immune systems of some women aren’t responding correctly to their partner’s triggering molecules.

In the past, blame has generally been put with the woman if a couple is struggling to conceive and the man has healthy sperm.

But Professor Robertson says her findings show there may be another element to it and with further research there may be tests and treatments later down the track.

The research has primarily been on mice and pigs, but Professor Robertson says there is some indication that it will have the same or similar effect on human females.

“We’ve discovered that there are signalling molecules in the seminal fluid, so that after coitus when that fluid travels from the male to the female reproductive tissues it activates gene expression changes and also changes in the female immune system that increase the likelihood of a pregnancy occurring,” she said.

“At the moment we’ve done lots of work on mice and pigs and we’ve done a little bit of work with human cells and we’ve found if we put seminal fluid on cells in vitro that we get the same kind of changes in human cells.

Professor Robertson says this discovery could be extremely important from an evolutionary perspective, because it means the female body has the ability to decide when the time is right to fall pregnant.

The University of Adelaide research team is looking for female volunteers from 18-40 who have had a tubal ligation, but are in a stable, sexually active relationship.

Via: abc.net.au

University of Adelaide professor Sarah Robertson said her research suggested that sperm contains “signalling molecules” that activate immunity changes in a woman so her body accepts [...]]]> A woman’s body may be unconsciously selective about sperm, allowing some men’s to progress to pregnancy but killing off the chances of less suitable matches, an Australian researcher said Wednesday.

University of Adelaide professor Sarah Robertson said her research suggested that sperm contains “signalling molecules” that activate immunity changes in a woman so her body accepts it.

But some apparently healthy sperm failed to activate these changes, leading to the suggestion that the female system can be “choosy” about its biological mate, she said.

“It’s rather like a two-way dance,” Robertson said.

“The male provides information that increases the chances of conception and progression to pregnancy, but the female body has a quality control system which needs convincing that his sperm is compatible.

“That’s where the dance can go wrong with some couples – if the male signals are not strong enough, or if the female system is too ‘choosy’.”

Robertson said sperm was more likely to fail if the woman had not previously been exposed to that man’s semen for at least three months.

“We used to think that if a couple couldn’t get pregnant, and the man’s semen test was normal, the problem lay with the woman. But it appears this is not always the case,” Robertson said.

The researchers plan to continue their work, which they hope will lead to improved treatments for infertility and miscarriages. – AFP

Via: iol.co.za

BeautifulPeople.com has always opened its doors and membership to people who are beautiful. However they have been deluged with demands for the sperm and [...]]]> New York, Jun 23 (THAINDIAN NEWS) BeautifulPeople.com has launched a controversial virtual sperm bank. According to Sky News, they have launched the egg and sperm bank for people who want beautiful children.

BeautifulPeople.com has always opened its doors and membership to people who are beautiful. However they have been deluged with demands for the sperm and eggs of the pretty people, so they had no option but to give in to popular demand and create a virtual egg and sperm bank. However they are facing a lot of ridicule and criticism from a number of quarters for this step.

The founder of the website Robert Hintze said that, “Initially, we hesitated to widen the offering to non-beautiful people. But everyone — including ugly people — would like to bring good looking children into the world, and we can’t be selfish with our attractive gene pool.”

The owners of the website also added that they think that every parent would want to have a pretty child, if they had the choice, hence they implemented the idea. However the idea is not without its critics. Dr. David King who belongs to the watchdog group Human Genetics Alert says that this idea is “dangerous for our society.”

Via: thaindian.com

Factors such as hormone treatment, alcohol consumption, obesity and giving birth to a first child later in life have all been linked to a higher risk of [...]]]> AFP – Hormone replacement therapy and lifestyle choices do not boost the risk of breast cancer associated with a dozen common genetic mutations, according to a study published Wednesday.

Factors such as hormone treatment, alcohol consumption, obesity and giving birth to a first child later in life have all been linked to a higher risk of breast cancer.

A number of common genetic variations also correlate with the disease, albeit weakly.

Earlier research suggested that combining the two types of risk factors could amplify the overall danger, but results were inconclusive.

To help tease apart genetic and non-genetic influences, scientists led by Ruth Travis at the University of Oxford examined the medical histories of some 17,350 women, 7,160 of whom had developed breast cancer.

All of the participants provided blood samples for genetic testing and information on lifestyle habits. Most of the women were post-menopausal.

The researchers looked for 12 variants in the women’s DNA known to boost the danger of cancer.

They also measured 10 environmental risk factors: age at puberty, number of births, age at first birth, breastfeeding, menopausal status, age at menopause, use of hormone therapy, body fat, height and alcohol intake.

Surprisingly, none of the 120 possible match-ups between a single genetic variant and a behavioural or body-type risk factor showed a statistically significant increase in breast cancer risk.

“There was no convincing evidence for gene-environment interaction,” the researchers concluded.

The study did not cover data on the BRCA1 and BRCA2 genes, which have a far stronger association to breast cancer than the other genetic variants examined but are much rarer.

“Genes account for only a small proportion of breast cancers for most women and for most women the main risk remains the lifestyle factors,” said Oxford’s Jane Green, a co-author of the study.

Via: france24.com

The disorder known as Fabry disease is characterised by attacks of burning pain in the hands and feet, dark nodular skin lesions and progressive renal insufficiency.

It is caused [...]]]> ISLAMABAD: A rare genetic disorder may be responsible for causing strokes in young people, though the condition’s progress can be slowed using enzyme replacement treatment, says a study.

The disorder known as Fabry disease is characterised by attacks of burning pain in the hands and feet, dark nodular skin lesions and progressive renal insufficiency.

It is caused by a missing or faulty enzyme needed by the body to process oils, waxes and fatty acids, reports the online edition of BBC News.

These lipids build up to harmful levels in the eyes, kidneys, nervous system, and cardiovascular system. People with the disease can die prematurely because of renal, cardiac or cerebrovascular complications.

The researchers at University of Rostock, Germany, led by Arndt Rolfs, carried out genetic screening of over 700 adults suffering from unexplained strokes to find out whether they had Fabry disease.

They found that four percent of the studied people, aged 18-55 years who had a stroke, also had Fabry disease. The strokes occurred about a decade earlier in people with the condition, they said.

The researchers found that nearly five percent of the male stroke patients and just over two percent of the female patients had genes linked to Fabry disease.

According to the scientists, this could mean that one in 100 of all young people suffering from strokes may have Fabry disease.

This study also found that the average age for a man with Fabry disease to have a stroke was 38, while for women, it was 40.

For men and women who did not have Fabry disease, the average age at which they had a stroke was 48.

Via: allvoices.com